Electromagnetic pump



` Sept. 7 1.926.

H. WALLACE ELECTROMAGNETI C PUMP llllllll/ v mummy Patented' Sept. 7,1926.

,UNITED STATES N 1,598,792V PATENTl OFFICE.

HUGH WALLACE, or DAYTON, OHIO, :AssIGNoR To GENERAL irorORs RESEARCH CORPORATION, or DAYTON, OHIO, AcoaroRA'rION or nnrJAwARa` ELECTROMAGNETIC PUMP.

Application led August 3, 1925.' Serial No. 47,678.

This invention relates to electrical li uid pumps and more particularly to gaso ine feed pumps for automobiles. of pump there is usually an electromagnet 6 which operates a pist-on in one direction,

and a spring for'moving the piston inthe 'opposite/ direction after the circuit of the electromagnet is interrupted. The magnet circuit is controlled by a pair of contacts',

10 which are. engaged and separated by the movements of the piston.

One of the objects ofthe present invention is to keep the contacts clean at all times,

in order to assure the continuous operation of the pump. 'In the present invention this object 1s accomplished by -providing a chamber, which is in communication with the main liquid. duct whichl includes the pump cylinder. The chamber is arranged so as 2" to be isolated from the liquid current, and also to trap a quantity of air above the liquid level in the chamber. 4The contacts are located in thepchamber above the liquid level, and are controlled by mechanism con nected with the piston and located wholly -/within the fuel passages of the pump so as to be entirely enclosed.

A further object is to provide ari-electro# magneticvpiston pump in ywhich the contactswhich control the electromagnet are opened or closed onlyafteithe piston has made substantially a full stroke. In the present invention this is accomplished by. providing the pump with a movable magnetizable body or auxiliary armature in addition to `the iston, which is'magnetizable, and in provlding a lost-motion connection between the piston and the auxiliary armature. The auxiliary armaturev is connected with one of the contacts" and is so located in the magnetic circuit that, while theelectromagnet is energized,v the armature is-'L'held magnetically in position to maintain the contacts closed until the piston strikes the armature inmoving toward a stationary core vof the magnet. The contact-s are held apart.

by a li ht spring until the piston has been moved rom the stationary core nearly afull stroke by a spring which is stronger thank the spring whlch tends to separate the con- A,Furthern objects 'and advantages Of the 'sent Jinvention will be apparent from the gllowing description, reference being had to theaccompanying drawings, whereln pre- In this type fcrred forms of the present invention are clearly shown.

Figures 1 to 3 inclusive of the drawings are sectional views of dili'erent forms of pumps embodying the present invention.

In the modiiicationshown in Fig. 1, the main fuel duct of the'pump is provided by a tube -20, to which is att-ached by a plug 21, a well 22enclosing a strainer 23. The well member 22 isltapped at 24 for receiving a-.G l

pipe connection leading fuel into the ump. The fuel. duct includes also a cylin er 25 surrounding a'portion of the tube 20. The

cylinder 25 supports a coupling 26 which is tapped at 27 to receive a pipe connecting 70 the pump with a vessel, for receiving liquid, such as the float bowl of a carburetor. The cylinder .25 receives a iston 30 which is moved upwardly, into t e position shown,` by spring 31, and downwardly by an electromagnet 32 surrounded by a housing cupl 33 having a cover 34 which supports a tube 35 surrounding the cylinder 25. The mag netic circuit of the magnet includes the tube or stationary core 20, cup 33, cover 34, tube 35 and the piston 30. `These parts are of magnetizable metal, while the cylinder 251 is of non-magnetizable metal. Movement of the piston 30 toward the tube'20 is limited by a non-magnetic stop 36. Piston 30 car'- 85 ries a pump-inlet valve 37, and the'connec--' tion 26 carries the outlet valve 38. Reci rocation of the piston 30 will cause t e valves to open and close alternately in the usual manner.l

The pump is preferably disposed vertically, as shown in Fig. 1. The tube 20 is connected by a transverse, substantially horizontal passage 40 with a spur duct 41 which provides a chamber, which is vertically dis- 95 posed and is isolated from the current of liquid flowing upwardly through the plug 21 and tube 20. The upper end of the chamber 41v is closedby a plug 42, so that a quantity of. air will be trapped within the 100 chamber 41 above the liquid level therein. I lThe plug 42 insulatinglV supports a rod'43 carrylng at its lower en a contact 44 which cooperates with a contact45v supported atthe upper end of a rod 46.. Rod 46 slides 105 through a 'guide 47 which is maintained against the lower end ofthe plug 42 by spring 48. v The lower end of the spring. 48 bears against a guide 49 into which the rod `46.is threaded. Rod 49 bears against a lll).`

lever 50 whichl is provided with .a ball 51 pivotally received by a plug '52,which closes the outer end of the passage 40. The spring 31 maintains, in the position shown, a yoke' is connected by a spring conductor 61 with a metal hub' 62 which is rotatable around a bushing 63 carried by a non-conducting block 64 supported bythe magnet cover 34.l

The sleeve 63 is connected by a wire 65 with one end of magnet winding 32. The other end of the magnet winding 32' is con-A nected by a switch with one terminal of a current source, such as a .storage battery. It is customary in automobiles to ground one terminalof the storage battery upon the vehicle frame. pump shown, is mounted upon the' engine frame of an automobile, a circuit 'will be made from the contact `to the grounded side of the storage battery.

.The contacts 44 and '45 are normally closed and the piston 30 is normally in its upper position, as shown in Fig.'1. To operate the pump, it'is connected by the switch reerred to, with the current source. The magnet winding 32 is energized and the pump piston 30- is attracted downwardly against the spring 31. During this downward movement, the'iianges 54 of the yoke 53 will first release the iange 55 and then engage the flange `56 toward the end of vdownward travel of the piston 30. While the flanges 54 are between the flanges 55 and 56, the contacts 44 and 45 remain closed in spite .of the tendencyof spring 48 to separate them, because' the auxiliary armature 58 tends to move upwardly while thetmagnet is energized. The attraction of the piston 30 downwardly ',isvgreater than the attraction of the armature 58 upwardly so that, the rod 57 will be moved downwardly after anges 54 engage flange 56.. This will cause the contact 45 to be moved downwardly out of engagement with the contact 44. The circuit Aof the magnet will, therefore, be broken and spring 31 will be released to move the iston'upwardly. Toward the end of upward) 54 'of the' yoke 53 wi engage the collar Jilangev 55 andwillpull the lever 5 0 upwardly.- The spring l48gtends to .maintain the contact 45 out iiengagement with th(J contact`44, but the spring 31 is strong. enough to. over co rne the-spring 48, sojthat ailter t e Therefore, when the spring 48, Ishown in Fig. 1.

vsubstantially l stroke. The rod 77 constitutes an auxiliary travel of thelpiston 30,-the flanges substantially the entire downward travel of the piston, and out of engagement during a substantial portion of its upward travel. In this manner, the rate of operation of the piston will be low and its stroke will be relatively long, as compared with piston movements at a rapid rate and through a very short am litude. This mode of operation is desirab e or'long life and economy in operation. The modification from Fig. 1, in that the contact 44 is carried by a scr'ew 7 Oadjustable through a bushing' 71 which is insulatingly supported by a plug 73 closing the upper end of thechamber 41a. .The screw 70 is maintained in adjusted position by a nut 74, the upper end of which receives the spring conductor 61. The contact 45 is mounted upon a rod 46al having a guide 49, and a spring 48a located between the guide 49a and a guide 47a, in order to have the same function. as the The rod 46JL bears against a lever 50a having a' ball-end 51a carried by a socket plug 52". The other ball-end 75 of the lever 5()a is received by an opening'76 in a magnetizable rod 77 carrying at its lower end a guide 78, andat: its upper end a screw 79 and a washer 80. The underside of the head of screw 79 is normally engaged by the ilanges 54 of the yoke 53. Thus the head of screw 79 performs the function of the lian e 55 in Fig. 1. The washer 80 performs the unction of 'the flange 56 in Flg.l 1.l The mode of operation of the 'pump shown in Fig. same as that in Fig..1,-one of the features beingthat the contacts 44 and 45 are not separated until the flange 54 engages the washer 80, or not until the piston r30 has completed .its downward armature having the same function as the armature 58 in Fig. 1. I

The forni of the invention shown in Fig, 2 diers from Fig. 1 also in the manner of constructing the fuel passages. A member 90 is provided with a horizontally-disposed passage, including the passage 40 and a passage 61, which is separated from the'passage 40 by the magnetizable tube 20, which extends through the bottom and top walls of opening 20b connected with the passage 40. The .liquid-inlet passage `91 is connected by a -hole 92 with the interior of a well 93 whic is attached fby a screw 94 to the tube 20.

the member 90,l and is provided with a side 'Ihe liquid 'passes through a screen 95 and through side openings 96 into 1the interior' of the tube 20a.

Fig. 3 shows still another form of the inventio, in which the pump vmagnet cylin-l der, and piston and valves are inverted. A member `100 provides passages 101 and 102, which are separated by a screw plug 103. Passage 102, with which the inlet' pipe .is connected, commioinicates with ahole 104 within the interior of' a well 105 attached by a screw 106 toa vertical tube 107 integral with'the member 100. Liquid passes throu h a screen 108 and side openings 109 into t e tube 107 and thence into the passage 101. Passage 101 is connected with a magnetizable tube 1.10 through a side opening`109 therein, the tube 110 being supported by the member 100. The tube 110 corresponds to the elements 20 and 20, shown in the other views, and supports in an invertedposition the pump, piston, cylinder and electromagnet. 4

The duct member 100 includes'a spurpas- Sage 111, which providesa chamber located out of the 'liquid current through the passage 101. The chamber 111 isv closed by a plug 112, so that it is adapted to tra a quantity' of air above the surface of the iquid which is received bythe chamber 111. The plug 112 insulatingly supports the adjusting screw 70, which has been described in con neetion with Fig. 2. 'The screw 70 is held in adjusted .position by nut 71 Contact 44, which lis supported the screw 70, cooperates with the contact carried at the upperendof rod 46" having a uide 491 and extending through a guide 4 b which is held in position by a spring 48". The rod 46b engages a lever 50b pivoted at 51" and having a ball-end 75" received by a recess 7 6", Recess 7 6b is provided by a magnetizable-rod 113. Rod 113 is connected @in spaced relation to a sleeve 114 by a magnetizable tube 115 constituting an auxiliary armature havin thefunctions of armature 58. A rod 116 is provided with a head 117 of lesser vertical dimension than the distance between the members 113 and 114. The rod 116 passes through a hole in the block 114 and is attached at its lower end to a yoke.

118,- which is maintained by the spring 31 against the piston 30. It is apparent, therefore, that the lhead 117 and the rod 116 performs the functions ofthe flanges 55 and 56 of the collar, which is attached to the rod 57 in Fig. 1.

In the modification shown in 3, the

contacts 44 and 45 are normally closed and inst the i .f 3. en the piston 30 wil be moved upwardly'l and the head r117 will release'the block 113,`so that 'the spring 31'may move the piston 30 downwardly. The cont-act 45 will remain out of engagement with the'contact 44 until a substantial downward movement of the piston J30 has taken place. Then this has occurred,-

the head 117 will engage the block 114 and will cause thestem 46h to moveA upwardly to engage the contacts again. Therefore, it is .apparent that in this form of the inveiition, as in the other forms, the opening and closing of the contacts occurs only as the piston nears the ends of its travel;

In all the forms of the invention, the contacts arelmaintained in an isolated chamber and aboveV the surface of the liquid which may enter the chamber. Thus the possibility of particles of'dir-t getting upon the contacts is minimized.

While the forms of embodiment of the invention asherein disclosed, constitute preferred forms, it is' to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed'is as follows: Y l' 1. A liquid'pump comprising, in combination, a duct for the lowof 'liquid'. means for causin liquid to flow through said duct and including a. reciprocating member, a chamber connected with said duct but isolated from the current of liquid'in said duct and adapted to trap a uantity of air above the surface of the liquid therein, an electromagnetfoigoperating said member, contactsA in said chamber above the liquid surface therein, and mechanism connected with said memberand extending from the duct into the chamber' for opening and closing the contacts. Y y p 2. A liquid ump comprising, in combination, a liquid) duct including a pump cylinder,- a piston in said cylinder, a vertical chamber connected with said duct but arranged to be 'isolated from the current of liquid through said duct and to trap .a quantity of air above the liquid s urface therein, an electromagnet for operating the piston, a pair of .contacts forcontrolling the magnet located above the liquid level in said chamber, and `mechanism connecting the piston with one .of thegcontacts.

3. A liquidv ump comprising, in combination, a liqui duct including a verticallydisposed pump cylinder, a piston within the ill",

cylinder, a vertically-disposed .chamber \dis posed out of the liquid current in said duct and arranged to trap aquantity of air above the liquid level therein, a transverse passage connecting the cylinder and chamber, a pair of contacts located in said chamber above the liquid level, mechanism connecting the piston and one of the contacts and including a lever loc ated.in the transverse passage, and an electromagnet controlled by the contacts.

LA liquid pump comprising,` in combination, a liquid duct having a spur duct out of the liquid current and providing a chamber adapted to trap a quantity of air above the surface of liquid therein, a piston in the liquid duct, contacts in the chamber above the liquid level therein, mechanism located wholly with the duct and spur for connecting the piston and one of the contacts and including a motion-reducing lever between the piston and lever, and an electromagnet for operating the piston controlled by the l contacts. r i

5. A liquid pump comprising, in combination, a cylinder, a movable piston, an electromagnet for moving the piston, contacts controlling the magnet circuit, means for controlling separation of the contacts by motion of the piston and including an auxiliary armature in the magnetic circuit of the electromagnet and having av lost-motion connection with the piston.

6. A liquidy pump compr1sing,`in'combi nation, a cylinder, a magnetizable piston, an

electromagnet'v having .a tubular core in proximity to the piston, contacts controlling the magnet circuit, and connectlons between the piston and one of the contacts including lmechanism comprising a spring tending to separate the contacts and a magnetizable body having a lost-motion connection with the piston and magnetically resisting separat-ion of the contacts by the last-mentioned spring but yielding to the movement of the pistonx after the lost motion is .taken up during movement of the piston by magnetic fonce, the last-mentioned spring being overcome by the first-mentioned lspring whereby the contacts are closed by the spring-pro duced movement of the piston after the lost motion is taken up.

8. A liquid pump comprising, in combination, a displacement member, inlet and outlet valves, an inletchamber, an electromagnet for operating the displacement member, contacts locatedlwithinwthe inlet' chamber and controlling ithemagnet, and

means for controlling` the separation and. closin of the contacts including a magnetiza le member in the magnetic circuit of the ma et and having a lost-motion connection with 4the displacement member.

In testimony whereof I hereto aiiix my signature.

' HUGH WALLACE. 

